Highlanders co-captain Nasi Manu has succumbed to injury and is in doubt for their opening match against the Blues in Dunedin on February 22. The 25-year-old suffered a small tear in his pectoral muscle while bench-pressing weights in pre-season training with the Highlanders.

Manu is the fifth Canterbury-based player to succumb to an unusual pectoral injury in the last eight months and joins lock Dominic Bird, hooker Codie Taylor, flanker Matt Todd and prop Sione Faletau, all Canterbury representatives, who have been unlucky to suffer from pectoral muscle problems since May last year.

The No. 8, who will be co-captaining with Conrad Smith will be bitterly disappointed with the turn of events after suffering a serious foot problem in his side's first match against the Chiefs in Dunedin last year and didn't take the field again until he represented Canterbury in September.

Such injuries are considered rare in rugby but Crusaders head coach Todd Blackadder, who lost Bird and Taylor when they required surgery to repair ruptured muscles during the Super Rugby season, said the franchise hadn't made dramatic changes to their training programmes.

''No we haven't. But we have had more a running-based programme this year, just because of the way we feel the game has evolved. We are doing a lot of cross-fit stuff, which is really good for overall strength and power," Todd Blackadder told Rugby Heaven.

''And we are still doing a lot of that (strength and power work) but it is more of a running-based programme which should serve us well.''